The present invention relates generally to chucks for use with drills or with electric or pneumatic power drivers. More particularly, the present invention relates to a chuck of the keyless type which may be tightened or loosened by hand.
Both hand and electric or pneumatic tool drivers are well known. Although twist drills are the most common tools on such drivers, the tools may also comprise screwdrivers, nut drivers, burrs, mounted grinding stones, and other cutting or abrading tools. Since the tool shanks may be of varying diameter or of polygonal cross-section, the device is usually provided with a chuck that is adjustable over a relatively wide range. The chuck may be attached to the driver by a threaded or tapered bore or any other suitable means.
A variety of chuck types have been developed in which a gripping mechanism is actuated by relative rotation between a chuck body and a sleeve. In an oblique jawed chuck, for example, a body member includes three passageways disposed approximately 120.degree. apart from each other. The passageways are configured so that their center lines meet at a point along the chuck axis forward of the chuck body. The gripping mechanism includes three jaws constrained by and movable in the passageways to grip a cylindrical tool shank disposed approximately along the chuck's center axis. The gripping mechanism also includes a nut that rotates about the chuck's center and engages threads on the jaws so that rotation of the nut moves the jaws in either direction in the passageways. The body is attached to the driveshaft of a driver and is configured so that rotation of the body in one direction with respect to the nut forces the jaws into a gripping relationship with the tool shank, while rotation in the opposite direction releases the gripping relationship. Such a chuck may be keyless if it is rotated by hand. One example is disclosed in U.S. Pat. No. 5,125,673 entitled "Non-Impact Keyless Chuck," commonly assigned to the present assignee and the entire disclosure of which is incorporated by reference herein.
Various configurations of keyless chucks are known in the art and are desirable for a variety of applications. Keyless chucks actuated by relative rotation between a sleeve and a chuck body generally include means to control the rotational position of the sleeve and the body. For example, a first sleeve may be provided in communication with a nut as described above while a second sleeve, which is independent of the first sleeve, may be attached to the body. Thus, a user may rotate the first sleeve with one hand while gripping the second sleeve with the other hand, thereby holding the body still. Alternatively, in some devices in which only a single sleeve is provided, a user may grip the single sleeve and actuate the tool driver to rotate the spindle, thereby rotating the chuck body with respect to the sleeve. In addition, a mechanism may be located in the driver to lock the spindle of the driver when the driver is not actuated, thus enabling use of a single sleeve chuck.